TPS63000 and TPS63001 output switching noise

You have to be careful when measuring switching noise.  Make sure to measure directly across the output capacitor.  Use a very short (< 1cm) ground lead.  "Tip and ring" method is best.  You may also be able to decrease switching noise with some high frequency bypass capacitors on by including an RC snubber from SW to GND.

Hello John,

 Thanks for assisting...Customer is still seeing quite a bit of noise, He is willing to send plots. He is wondering if you have any app notes on the snubber suggestion or what might be expected with regard to noise? It does not appear there is charactorization in the datasheet for it. He is hoping not to chase his tail if performance is not obtainable. Would it be possible for TI to do a simple measurement with the dev board with 3v->5v conversion at around 1A

I don't directly support those devices.  I occasionally will comment on posts that are of general interest such as this.  Let me see if I can direct this to the appropriate apps support person.  I do have a word doc on snubber selection if you contact me directly.

You can attach the waveforms to this forum thread.  It is likely simply a matter of using correct measurement technique.

The D/S shows the output ripple in Figures 8 and 9.  It is very low.

Hi Sevrum,

As John and Chris mentioned, you should first check your measurement technique. We have a series of videos under our "Engineer IT" Series, one of which discusses probing techniques for measuring noise on power supplies:

Engineer IT - How to test power supplies - Measuring Noise

http://focus.ti.com/general/docs/video/Portal.tsp?lang=en&entryid=0_mbl8701d

As John discussed, if a snubber circuit is necessary then here are some useful links to help you get started:

Minimizing Ringing at the Switch Node of a Boost Converter

http://www.ti.com/lit/an/slva255/slva255.pdf

Snubber Circuit Practical Tips

http://www.ti.com/ww/en/analog/power_management/snubber_circuit_design.html

Thanks!

Alex